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In a WLA problem, one of the most essential requirements is the assurance of a minimum concentration of dissolved oxygen (DO) throughout the river system in an attempt to maintain desired levels of aquatic biota. The constraint relating the response of DO to the additional of in-stream waste generally is defined by the Streeter-Phelps equation […]

The WLA problem, by nature, is a multiobjective problem involving several conflicting objectives. The treatment-equity constraint (Eq. 8.59c) is incorpo­rated for the purpose of fairness. Without it, any attempt to maximize waste discharge (or to minimize treatment cost) could result in allocating large quan­tities ofwaste to the upstream users, whereas the downstream discharges could be […]

Deterministic waste-load allocation model. Although any number of pollutants may be considered in the overall quality management of a river system, in this example, application a biochemical oxygen demand-dissolved oxygen (BOD-DO) water-quality model is considered. In LP format, the deterministic WLA model considered herein can be written as N Maximize ^^( Bj + Dj) j=i […]

Water-quality management is the practice of protecting the physical, chemi­cal, and biologic characteristics of various water resources. Historically, such efforts have been guided toward the goal of assessing and controlling the im­pacts of human activities on the quality of water. To implement water-quality management measures in a conscientious manner, one must acknowledge both the activities […]

In all fields of science and engineering, the decision-making process depends on several parameters describing system behavior and characteristics. More often than not, some of these system parameters cannot be assessed with certainty. In a system-optimization model, if some of the coefficients in the constraints are uncertain, the compliance with the constraints, under a given […]

A flood-damage-reduction plan includes measures that decrease damage by reducing discharge, stage, and/or damage susceptibility (U. S. Army Corps of Engineers, 1996). For federal projects in the United States, the objective of the plan is to solve the problem under consideration in a manner that will “… contribute to national economic development (NED) consistent with […]

The basic functions of highway drainage structures are (1) as hydraulic facil­ities to safely convey floods under highways during all but the most severe flooding conditions and (2) as portions of the highway to move highway traffic freely over stream channels. There are three general types of drainage struc­tures: bridges, box culverts, and pipe culverts. […]

Besides the economic factors that can be quantified in monetary terms in the design of hydrosystems, there are other intangible factors that are noncommen­surable and cannot be quantified. Some of the intangible factors might work against the principle of economic efficiency. Examples of intangible factors that are considered in the design and planning of hydrosystems […]

Conventional risk-based design and analysis ofhydrosystems requires informa­tion with regard to various flood-related damages. Such information requires an extensive survey of the type and value of various properties, economic andsocial activities, and other demographic-related information in the regions that are affected by floods. For areas where flood-related damage data are unavail­able, conventional risk-based analysis cannot […]

In risk-based and optimal risk-based designs of hydrosystem infrastructures, the thrust of the exercise, after uncertainty and risk analyses are performed, is to evaluate E( Dx) as the function of the probability density functions (PDFs) of loading and resistance, damage function, and the types of uncertainty considered. Conventional approach. In conventional risk-based design, where only […]